Abstract
Understanding the genetic basis of tetrodotoxin (TTX) accumulation and
resistance in animals could provide us significant insights into
adaptive evolution in ecological communities. It has been reported that
TTX resistance is possibly due to gene mutation in sodium channels.
Eating sea snail Nassarius has caused serious people poisoning and death
incident due to tetrodotoxin (TTX) accumulation in their body. Here we
conducted transcriptome analysis for both toxic and non-toxic
communities in two Nassarius species (Nassarius succinctus and Nassarius
variciferus) to reveal their genetic patterns of TTX accumulation and
resistance. For genetic expression, the cellular and metabolic process,
and binding and catalytic activity accounted for the top classification
categories for both species. The toxic communities generally produced
more up-regulated genes than non-toxic communities. The mostly different
expression genes among toxic and non-toxic communities mainly included
heat shock protein 83-like, cytochrome c oxidase subunit, WAS protein
family member 2, delta-aminolevulinic acid dehydratase, protein
transport protein Sec24D isoform X2 and so on, some of which referred to
detoxification. In mutation level, the sodium channel gene of N.
succinctus had one amino acid āLā that is different from that of other
animals. The transcriptome analysis of both toxic and nontoxic
communities in two Nassarius species provided important genetic basis
for adaptive evolution research of TTX accumulation and resistance.